Self-detachment and subsurface densification of dealloyed nanoporoust thin films

Link:
Autor/in:
Verlag/Körperschaft:
Hamburg University of Technology
Erscheinungsjahr:
2022
Medientyp:
Text
Schlagworte:
  • coarsening
  • dealloying
  • nanoporous metals
  • nanowires
  • Plateau-Rayleigh instability
  • surface diffusion
  • 620: Ingenieurwissenschaften
Beschreibung:
  • Experiment shows thin films of dealloyed nanoporous gold (NPG) spontaneously detaching from massive gold base layers. NPG can also densify near its external surface. This is naturally reproduced by kinetic Monte Carlo (KMC) simulation of dealloying and coarsening and so appears generic for nanoscale network materials evolving by surface diffusion. Near the porous layer's external surface and near its interface with the base layer, gradients in the depth-profile of a laterally averaged mean surface curvature provide driving forces for diffusion and cause divergences of the net fluxes of matter, leading to accretion/densification or to erosion/disconnection. As a toy model, the morphology evolution of substrate-supported nanopillars by surface diffusion illustrates and confirms our considerations. Contrary to cylindrical nanowires, the ligaments in nanoporous materials exhibit pre-existing gradients in the mean curvature. The Plateau-Rayleigh long-wavelength stability criterion is then not applicable and the disconnection accelerated.
Beziehungen:
DOI 10.1021/acs.nanolett.2c02666
Lizenzen:
  • info:eu-repo/semantics/openAccess
  • https://creativecommons.org/licenses/by/4.0/
Quellsystem:
TUHH Open Research

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Quelldatensatz
oai:tore.tuhh.de:11420/13603